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22 lines
595 B
Rust
22 lines
595 B
Rust
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//! Test that non-coercion casts aren't allowed to drop the principal,
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//! because they cannot modify the pointer metadata.
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//!
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//! We test this in a const context to guard against UB if this is allowed
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//! in the future.
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trait Trait {}
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impl Trait for () {}
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struct Wrapper<T: ?Sized>(T);
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const OBJECT: *const (dyn Trait + Send) = &();
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// coercions are allowed
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const _: *const dyn Send = OBJECT as _;
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// casts are **not** allowed
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const _: *const Wrapper<dyn Send> = OBJECT as _;
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//~^ ERROR casting `*const (dyn Trait + Send + 'static)` as `*const Wrapper<dyn Send>` is invalid
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fn main() {}
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